1. Field of Invention
The present embodiments relate generally to treating Type-2 Diabetes, obesity, and aid in weight loss by facilitating the delivery of under-digested nutrients within the gastro -intestinal tract without substantial tissue removal.
2. Description of the Related Art
Diabetes mellitus Type-2 is a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. There are an estimated 17.9 million people in the United States diagnosed with Diabetes, 90% of whom are Type-2.
Recently, it has been observed that gastric bypass procedures such as the Roux-en-Y Gastric Bypass (RYGB) employed to treat morbid obesity result in amelioration of Type-2 Diabetes. In five published studies summarized by Cummings, E. David, Overduin, Joost, Foster-Schubert, and Karen E. in Gastric Bypass for Obesity: Mechanisms of Weight Loss and Diabetes Resolution published in the Journal of Clinical Endocrinology and Metabolism 89 (6):2608-2615, a total of 3,568 diabetic patients undergoing RYGB, were examined and 82-98% of patients enjoyed complete remission of their disease, with most studies showing resolution in approximately 83% of cases. The reversal of impaired glucose tolerance without Diabetes was nearly universal. Patients whose Diabetes remitted were able to discontinue all diabetic medications and manifest normal fasting glucose and glycosylated hemoglobin levels.
Thus, gastric bypass procedure is a highly effective method to reverse Diabetes, which is traditionally regarded as a progressive, unrelenting disease. The most obvious mechanism to explain this effect is the beneficial impact of weight loss on insulin sensitivity. Indeed, patients who have lost substantial weight after RYGB display increased levels of adiponectin (which increases insulin sensitivity) and muscle insulin-receptor concentration, as well as reductions in intramuscular lipids and fatty acyl-coenzyme A molecules (moieties that cause insulin resistance). As predicted, insulin sensitivity increased approximately 4 to 5-fold after RYGB-induced weight loss.
The beneficial effects of RYGB on Type-2 Diabetes, however, cannot be accounted for by weight loss alone. Perhaps the most impressive observation is that previously diabetic patients typically discontinue all of their Diabetes-related medications at the time of discharge from the hospital after RYGB, long before major weight loss has occurred.
A proposed hypothesis for the anti-diabetic phenomenon is that gastric bypass procedures expedite delivery of under-digested nutrients to the hindgut. The presence of under-digested nutrients in the ileum suppresses gastrointestinal motility, gastric emptying, small intestinal transit, and thus, food intake. Neural mechanisms are implicated in this response, as well as hormones, including PYY, glucagon-like peptide-1 (glp-1), neurotensin, and enteroglucagon. Particularly, enhanced glp-1 secretion from facilitated delivery of nutrients to the hindgut may result in increased glucose tolerance and may account for anti-diabetic effects of gastric bypass procedures.
However, gastric bypass procedures are highly invasive and can carry a heavy toll. For example, morbidity rate is high with 11% requiring surgical intervention for correction. Additionally, post-treatment small bowel obstruction occurs at a rate between 2-6% and mortality rates are reported to be ˜0.5-1.5%. While surgery seems to be an effective answer, the high complication rates make the current procedures impractical for most patients. Furthermore, although laparoscopic techniques provide fewer surgical complications, patients are still exposed to high operative risk in addition to requiring an enormous level of skill by the surgeon.
Sleeve gastrectomy procedures and devices such as that disclosed in U.S. Pat. No. 7,025,791 have been proposed to sleeve or cover a portion of the gastro-intestinal tract to achieve similar results as the more invasive surgical procedures. However, one drawback of these devices is that nutrients travel at the normal rate if not slower to the distal portion of the small intestine, thus such devices may not promote glp-1 secretion. Furthermore, the distal sleeve of these devices may not be patent and thus contribute to more resistance.
To remedy the shortcomings, it would be desirable to provide novel methods, devices or systems that expedite the delivery of under-digested nutrients to the hindgut to treat Type-2 Diabetes, obesity, or facilitate weight lost without tissue removal. Additionally, it would be desirable for such methods and devices to be non-invasive such that treatment complications are minimized. Furthermore, it would be desirable for such methods and devices to achieve long-term benefits to the subject even after the removal of the device. At least some of these objectives will be met by the embodiments described below.